10 Gbit/s modulation performance of distributed feedback lasers for optical fiber communication systems

The authors present a comparison of the performance of amplitude-shift-keying (ASK), frequency-shift-keying (FSK), and differential-phase-shift-keying (DPSK) optical fiber communication systems which operate at 10 Gb/s with directly modulated 1550-nm distributed feedback (DFB) laser transmitters and conventional 1310-nm dispersion-optimized fiber. The performance of these systems was evaluated from computer-simulated eye patterns for both direct detection and heterodyne detection. With the narrow optical spectral widths of these signal formats, fiber chromatic dispersion limits of up to 70 km were obtained for transmission at 1550 nm using conventional 1310-nm optimized fiber. Experimental results which confirm the 10-Gb/s FSK and DPSK modulation capabilities of 1530-nm DFB lasers are presented